Go to a meeting today. Tell the mom you are going to a meeting and that you won't discuss it with her. But she can be assured you are working on things--and she can tell the bf.
Then tell the bf to stop channeling through his mother. It is her business because it is her son, but he needs to deal with you himself on this issue if he wants to deal with you himself on any issue.
I'm sorry you are struggling though. The most important thing, no matter what, is to avoid drinking today.